1. Field of the Invention
The present invention concerns an electrolyzer apparatus and method to produce high-pressure hydrogen at pressures up to 10,000 psig or higher, by means of electrolysis of water and without necessity of separate compression equipment. Direct electrolytic generation of such high-pressure hydrogen (and by-product oxygen) is attainable by the practices of the present invention.
2. Related Art
Electrolytic production of hydrogen is, of course, well known, as illustrated by U.S. Pat. Nos. 5,665,211 for “Electrolysis Apparatus for Producing Hydrogen”; U.S. Pat. No. 6,033,549 for “Method of Electrolysis”; U.S. Pat. No. 6,071,386 for “Electrolysis Apparatus; and U.S. Pat. No. 6,153,083 for “Electrolyzer Isolated by Encapsulation with Respect to Pressurized Water”.
Known electrolytic equipment, sometimes herein referred to as “electrolyzers”, using liquid electrolyte to generate hydrogen, operates in the following way. Two electrodes are placed in a bath of liquid electrolyte, such as an aqueous solution of potassium hydroxide (KOH). A broad range of potassium hydroxide concentration may be used, but optimally, a concentration of about 25 to 28% by weight KOH solution is used. The electrodes are separated from each other by a separation membrane that selectively allows passage of liquid but not gas through it. When a voltage is impressed across the electrodes (about 2 volts), current flows through the electrolyte between the electrodes. Hydrogen gas is produced at the cathode and oxygen gas is produced at the anode. The separation membrane keeps the hydrogen and oxygen gases separated as the generated gas bubbles rise through the liquid electrolyte. There is a disengagement space above the liquid electrolyte comprised of two separate chambers or two sections isolated from each other by being separated by a gas-tight barrier into two separate sections, one chamber or section to receive the hydrogen gas and the other to receive the oxygen gas. The two gases are separately removed from the respective sections of the disengagement pace for storage or venting.